22 N-m (~16 lb-ft). They're aluminum so be gentle. EDIT: just kidding, they are STEEL.

Bolt torque is a very complicated matter and has many variables that determine the necessary torque. In the case of the three bolts that hold down the oil filter housing, they are only compressing the profile gasket, so not much torque is required. When I did my gasket, I just tightened them down until they stopped. You'll feel it when they hit the stop point.

I went with gud'n-tight. Got all three down to where it just starts to add pressure to the housing and then tightened all to where it feels even to me. Don't worry, my elbow is calibrated. At work I always use a torque wrench of course, a lot.

If you're using a universal joint on the one hard to reach bolt and going directly overhead on the other two, well...you're doing gud'n-tight too, except two of your bolts will be the correct torque while that hard to reach one is going to be off, assuming you didn't recalculate the torque for adding on long extensions and wobbly adapters. Personally, I doubt it matters much unless you went crazy and extreme.